Two cases of normal pressure hydrocephalus caused by ependymoma of the cauda equina

Background: Normal pressure hydrocephalus (NPH) associated with tumors of the cauda equina is rare. Here, we report two cases of NPH attributed to cauda equina ependymomas. Case Description: A 63-year-old male presented with progressive gait disturbance, dementia, and urinary incontinence. When the lumbar MR documented an intradural tumor involving the cauda equina at the L2-L3 level; the tumor was excised; pathologically, it proved to be a myxopapillary ependymoma. Postoperatively, however, the patient’s continued gait disturbance led to a brain CT that documented ventricular dilation consistent with NPH; following ventriculoperitoneal (VP) shunt placement his symptoms improved. A 65-year-old female also presented with gait disturbance, dementia, and urinary retention. Here, procedures were performed in reverse. When a brain CT showed hydrocephalus, a VP shunt was placed. When symptoms persisted, a lumbar MR demonstrated a T12-L2 intradural tumor; following a lumbar laminectomy for tumor excision, symptoms stabilized. The pathological diagnosis was also consistent with a conus/cauda equina ependymoma. Over the next 10 years, the patient had residual bladder dysfunction (e.g., requiring straight catheterization), but had no shunt dysfunction. Conclusion: We observed two cases of ependymomas of the cauda equina and brain CTs documenting NPH that was successfully surgically managed with stabilization of neurological deficit. In the first case, L2-L3 laminectomy for tumor removal was succeeded by shunting for NPH, while in the second case, initial VP shunting for NPH was followed by a T12-L2 laminectomy for tumor excision.